Strong winds were seen as a factor in the crash of a small plane in Costa Rica that killed all 10 US passengers on board and two local crew members, according to officials and witnesses.

The accident, which occurred Sunday in the country's northwestern Guanacaste region popular with tourists seeking pristine tropical beaches, killed all on board the small Cessna 208 Caravan owned and operated by domestic airline Nature Air.

The plane burst into flames on impact, according to rescue officials and locals.

Costa Rica's civil aviation agency said the pilots had tried to land at Punta Islita, a beachside town in Guanacaste, earlier Sunday to get the passengers but aborted because of "the gusts of wind."

The aircraft was up-to-date with its certifications and had been inspected a month earlier, the agency said.

"There had been a lot of wind, really strong," one resident in the area told AFP on Monday.

She said when she and other locals arrived at the crash site, up a steep hillside, "we couldn't see, absolutely everything was black."

She added: "The front part of the plane was all on fire, and the tail part was the only bit intact."

Police and fire crews arrived within 25 minutes of the crash, which happened shortly after midday (1800 GMT), she said.

Another resident, Efrain Rojas, told the newspaper La Nacion that the plane was "too low" after take-off.

"It did a turn to the left. For us, it looked like some sort of problem, and it was trying to get back to the runway. With the turn it did, it had one wing up vertical, and the other hit the trees," he said.

"When we arrived, it was all in flames.... The plane, when it came down, apparently exploded, caught fire," he said.

- Family killed -

The plane came down minutes after taking off from a small sealed airstrip in Punta Islita, where the Americans had boarded.

"We can confirm the death of ten US citizens in an airplane crash in Costa Rica on December 31, 2017," a US State Department official said by email on Monday.

"We express our condolences to all those affected by this tragedy," the official said, adding that consular assistance was being extended.

An American family of five from the town of Scarsdale, a suburb of New York City, was wiped out in the crash, US media reported.

Bruce and Irene Steinberg and their three sons William, Zachary and Matthew were all killed while on a family vacation.

The other US victims were named as Thibault Astruc, Amanda Geissler, Charles Palmer, Leslie Weiss and Sherry Wuu.

The Costa Rican pilot was Juan Manuel Retana, 52. He was the cousin of former Costa Rican president Laura Chinchilla, who spoke of their ties on Twitter. His co-pilot was Emma Ramos, also Costa Rican.

Guanacaste is a popular vacation destination, especially this time of year, when US and European tourists arrive in bigger numbers for an end-of-year respite from the northern hemisphere's winter.

- 'Difficult moment' -

The process of recovering the bodies went into late Sunday, and their remains were transported to the capital San Jose on Monday.

Costa Rican President Luis Guillermo Solis expressed his condolences Sunday in a statement posted to social media.

Solis said his government "gives its commitment to do everything necessary to work with the relatives of the victims to give them what they need in this difficult moment."

Americans are by far the biggest group of tourists visiting Costa Rica, accounting for around 1.3 million arrivals per year in this nation of nearly five million.

Major air accidents are uncommon in Costa Rica.

The last comparable accident dates back to August 26, 2000 when eight foreign tourists and two Costa Rican crew members all died when their small plane crashed into the side of a volcano near San Jose.